1) Field of the Invention
The present invention relates to a paper handling apparatus and a printing apparatus, both having a function of stacking sheets of paper which have continuously undergone printing or a function of cutting continuous paper which has undergone printing and which has been fed continuously and more particularly, to a paper handling apparatus and a printing apparatus which are suited for printing a large volume of data transmitted from a large-scale information processing system or similar.
2) Description of the Related Art
In recent years, information processing systems assume, for example, the form of a network system in which a host computer, such as a super-computer, is connected with terminals, such as personal computers, office computers, and similar, through a network similar to LAN so as to establish mutual communication.
A printing apparatus (electrophotographic printer or similar, for example) is connected to such an information processing system through a network. The printing apparatus is adapted to continuously print, at a high speed on a large quantity of printing paper (continuous paper or continuous form), a large volume of print data, which are transmitted from the host computer, and the individual terminals through the network.
Since printed paper is ejected from the printing apparatus in a large quantity, the printed paper needs to be handled properly on the paper ejection side of the printing apparatus. For example, the printed paper needs to be stacked for temporary storage.
In this connection, an apparatus for handling printed paper is disclosed, for example, in Japanese Patent Application Laid-open Nos. 3-264470 and 2-243464.
The apparatus described in Japanese Patent Application Laid-open No. 3-264470 is provided with a plurality of shelves for stocking printed paper in a sorted manner and transfer means for transferring printed paper to the shelves. In the apparatus, printed paper is transferred and stored in a sorted manner, whereby a print requester, who is familiar with sorting rules, can readily get the results of printing from a relevant shelf.
According to the apparatus described in Japanese Patent Application Laid-open No. 2-243464, printed paper is stacked on a stacker table, which is moved so as to slightly shift the stacking position of printed paper for each job (print process unit). With this structure, printed paper for each job can be readily identified.
According to a conventional practice, when a printing apparatus is adapted to perform printing on continuous paper, a paper handling apparatus (paper cutting apparatus) having a function of cutting printed continuous paper at suitable positions is provided on the paper ejection side of the printing apparatus. FIGS. 31 and 32 show examples of a printing apparatus provided with such a paper handling apparatus.
As shown in FIGS. 31 and 32, a printing apparatus (printer) 101 is provided with a paper hopper 102 which contains blank continuous paper 100 folded at perforations. The continuous paper 100 fed from the paper hopper 102 has continuously undergone printing at an image transfer section 103. The printed continuous paper 100 is ejected from the printing apparatus 101 and enters a paper handling apparatus 110 (paper cutting apparatus) which is connected to the printing apparatus 101 at its paper ejection side (latter part).
The paper handling apparatus 110 is provided with a cutter 111 for cutting the printed continuous paper 100 at suitable positions. The cutter 111, as described later, cuts the continuous paper 100 along perforations at a suitable number of pages (a portion of paper between two lines of perforations is handled as one page) or in response to an instruction from a host computer (host apparatus) 105.
The paper handling apparatus 110 is provided with a paper stacker 112 in which the printed continuous paper 100 is stacked while being folded at perforations. When a suitable quantity of the printed continuous paper 100 accumulates in the paper stacker 112 and when the stacked paper is separated by cutting with the cutter 111 from the continuous paper 100 on the side of the printing apparatus 101, a block of thus separated stacked continuous paper 100 is ejected from the paper stacker 112.
In FIGS. 31 and 32, reference numeral 104 denotes an operator panel which is located on the printing apparatus 101 and allows an operator to make various kinds of settings for the printing apparatus 101 and the paper handling apparatus 110. Reference numeral 105 denotes a host computer (host apparatus), which outputs various instructions (a request for print, etc.) to the printing apparatus 101 so as to control the printing apparatus 101.
The host computer 105, shown in FIG. 31, however, has only software 105A for the printing apparatus 101 and is adapted to control the printing apparatus 101 according to the software 105A without considering the cutting function of the paper handling apparatus 110. On the other hand, the host computer 105, shown in FIG. 32, has software 105B for the paper handling apparatus 110, in addition to the software 105A for the printing apparatus and is adapted to control a cutting operation performed by the cutter 111 in the paper handling apparatus 110 and printing of an intermediate separator, as described later, according to the software 105B for the paper handling apparatus 110, while controlling the printing apparatus 101 according to the software 105A for the printing apparatus.
The respective operations of the apparatuses shown in FIGS. 31 and 32 will now be described.
In the printing apparatus 101, shown in FIG. 31, print data received from the host computer 105 are analyzed and expanded, and then the print data are printed at the image transfer section 103 on the continuous paper 100 which is fed from the paper hopper 102. The printed continuous paper 100 is transferred from the printing apparatus 101 to the paper handling apparatus 110 and stacked in the stacker 112.
In the printing apparatus 101, shown in FIG. 31, an operator can specify, from the operator panel 104, the number of pages to be printed before the continuous paper 100 is cut by the cutter 111 in the paper handling apparatus 110. When the number of printing pages is specified, after printing on the continuous paper 100 as many pages as specified, the printing apparatus 101 outputs an instruction to the paper handling apparatus 110 to being cutting, and thus the cutter 111 performs a cutting operation.
When the printed continuous paper 100 is cut by the cutter 111, the result of printing for one job may be divided into a plurality of blocks (three blocks in FIG. 31) in some cases. If the blocks of printed paper (continuous paper 100) are randomly ejected from the paper handling apparatus 110, their mutual relation (order) and even whether or not blocks are of the same job may become uncertain.
To prevent the above-described problem, information indicative of the same job, i.e., an "intermediate separator," may be printed on the top page of a block of the continuous paper 100 and the bottom page of a subsequent block of the continuous paper 100. In this case, the host computer 105 needs to send print data about an intermediate separator, both before and after the instruction to begin cutting, to the printing apparatus 101.
In the example shown in FIG. 31, the host computer 105 controls the printing apparatus 101 according to the software 105A for the printing apparatus, but the software 105A is not adapted to recognize how many pages of the continuous paper 100 are to be printed before the continuous paper 100 is cut and the positions at which the continuous paper 100 cutting is performed. Accordingly, an intermediate separator cannot be printed, and hence a released block of the printed continuous paper 100 fails to bear an intermediate separator on the top/bottom page.
In this connection, in the example shown in FIG. 32, the host computer 105 has the dedicated software 105B for the paper handling apparatus (paper cutting apparatus) 110 for controlling a cutting operation of the cutter 111 in addition to the software 105A for the printing apparatus.
The dedicated software 105B for the paper handling apparatus manages the cutting position of the continuous paper 100. When an instruction to begin cutting is sent to the printing apparatus 101, the software 105B sends print data about an intermediate separator and an instruction for printing an intermediate separator, both before and after sending an instruction to begin cutting, to the printing apparatus 101, whereby the intermediate separator is printed on a page before and after each cut position. The instruction to begin cutting is sent to the paper handling apparatus 110 via the printing apparatus 101. In response to the instruction to begin cutting, the cutter 111 cuts the continuous paper 100 along perforations which separate two pages each printed with the intermediate separator.
As a result, as shown in FIG. 32, an intermediate separator indicative of the same job is printed on the top and/or bottom page (boundary page) of separate blocks of the continuous paper 100. Thus, an operator, for example, can recognize which block belongs to which job by viewing only the intermediate separator.
In FIG. 32, the top face of each block bears the above-described "intermediate separator," but in actuality, specific print data indicative of a job which are received from the host computer 105 are printed thereon.
However, the apparatus described in Japanese Patent Application Laid-open No. 3-264470 requires shelves for individual destinations. As destinations increase, the space required for shelves increases, leading to an increase in the costs of the apparatus.
As for the apparatus described in Japanese Patent Application Laid-open No. 2-243464, when a large volume of printing is executed in response to a request from a large-scale information processing system, a quantity of printed paper, which is stacked on the stacker table, will soon reach a stack limit quantity, wherein printed paper is disabled from being stacked further on the stacker table. When the stack limit quantity is reached, the printing apparatus stops accepting a request to print. Thus, a host computer and terminals, which output a request to print to the printing apparatus, need to wait for printing to resume until a stack of printed paper is removed from the stacker table. Printing, therefore, needs to halt each time a stacked quantity of printed paper on the stacker table reaches a limit thereof, leading to a deterioration in printing efficiency.
In this connection, the stacker table can have a structure in which the stack table is lowered whenever printed paper is ejected thereon. With this structure, a stackable quantity of printed paper on the stacker table can be increased. Even if this structure is employed, a stacked quantity of printed paper on the stacker table will soon reach a limit thereof when a large volume of printing is executed. Hence, as in the case of the apparatus described above, the information processing system needs to wait for printing to resume until a stack of printed paper is removed from the stacker table in a suspended printing apparatus, leading to a drop in printing efficiency after all. In addition, when a large quantity of printed paper is stacked, a lower portion of the stack is difficult to take out due to the weight of printed paper stacked thereabove. This increases a burden on a person who comes to receive the result of printing.
Furthermore, the printing apparatus 101, provided with the paper handling apparatus 110 shown in FIG. 32, requires the host computer 105 to have the software 105B for controlling the paper handling apparatus 110. That is, attaching the paper handling apparatus 110 to the printing apparatus 101 requires software contained in the host computer 105 to be modified, leading to many additional man-hours and costs.
To solve this problem, a technique is proposed in which the printing apparatus 101 is provided with a circuit for generating print data about an intermediate separator on the basis of job information (see Japanese Patent Application No. 4-308358). This, however, involves adding a new circuit for printing an intermediate separator to the printing apparatus 101, leading to many additional man-hours and costs after all.
In the printing apparatus 101, provided with the paper handling apparatus 110 shown in FIG. 32, an operator (user) usually visually determines whether or not a current job is continued when a stacker full state (i.e., a state where a stacked quantity of the continuous paper 100 has reached a stacking limit of the stacker 112) occurs with the paper stacker 112. This causes an increase in the burden on the operator.
According to a proposed technique for solving this problem, when the number of printed pages, which is counted by the host computer (host apparatus) 105, reaches a predetermined value, the host computer 105 sends an instruction to the printing apparatus 101 so as to print a pattern indicative of a job being continued onto the continuous paper 100. This technique allows easy determination of whether or not a job is continued when the stacker becomes full. This technique is applicable to the printing apparatus 101 which handles paper of a fixed thickness, but is not applicable to a printing apparatus which handles paper of various thicknesses because the number of pages which makes the stacker full varies.
Also, in the printing apparatus 101 provided with the paper handling apparatus 110 shown in FIG. 32, when a minor paper jam occurs in the section between the transfer section 103 and the cutter 111, after the paper jam is solved by an operator, the printing apparatus 101 is usually controlled so as to perform a recovery printing for the portion of the continuous paper 100 which was located between the transfer section 103 and the cutter 111.
In this case, print data, which were printed on the portion of the continuous paper 100 between the transfer section 103 and the cutter 111 when a paper jam occurred, is printed again. Thus, an operator needs to check the printed continuous paper 100 page by page for redundant pages due to recovery printing and to remove the redundant pages. This imposes a heavy burden on the operator.